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A helicity proxy from horizontal solar flow patterns
Author(s) -
Rüdiger G.,
Brandenburg A.,
Pipin V.V.
Publication year - 1999
Publication title -
astronomische nachrichten
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.394
H-Index - 63
eISSN - 1521-3994
pISSN - 0004-6337
DOI - 10.1002/1521-3994(199907)320:3<135::aid-asna135>3.0.co;2-7
Subject(s) - physics , dynamo , vorticity , helicity , turbulence , northern hemisphere , dynamo theory , rossby number , solar dynamo , rotation (mathematics) , divergence (linguistics) , solar rotation , computation , potential vorticity , geophysics , classical mechanics , vortex , astrophysics , mechanics , magnetic field , solar physics , geometry , atmospheric sciences , mathematics , quantum mechanics , linguistics , philosophy , algorithm
Motivated by new observations of solar surface flow patterns of mesogranulation, theoretical computations of the horizontal divergence‐vorticity correlation are presented. Because of its close relation to the helicity in rotating turbulence such observations and discussions are of particular importance for the conventional dynamo theory. For the northern hemisphere we find a small, but always negative, divergence‐vorticity correlation. Both an analytical Second Order Correlation Approximation for slow rotation as well as a numerical simulation (originally done for accretion disks) for fast rotation yield very similar results.